scholarly journals Detection of Particulate Matter of Size 2.5 μm with a Surface-Acoustic-Wave Sensor Combined with a Cyclone Separator

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 398 ◽  
Author(s):  
Fung-Yu Kuo ◽  
Ying-Chen Lin ◽  
Ling-Yi Ke ◽  
Chuen-Jinn Tsai ◽  
Da-Jeng Yao
Keyword(s):  
Particulate Matter ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Limit Of Detection ◽  
Cyclone Separator ◽  
Saw Sensor ◽  
Well Design ◽  
Microcentrifuge Tube ◽  
Acoustic Wave Sensor ◽  
Positive Linear Correlation

A device to monitor particulate matter of size 2.5 μm (PM2.5) that has been designed and developed includes a surface-acoustic-wave sensor operating in a shear horizontal mode (SH-SAW) combined with a cyclone separator. In our tests, aerosols generated as incense smoke were first separated and sampled inside a designed cyclone separator; the sampled PM2.5 was then introduced into the sensing area of an SH-SAW sensor for detection. The use of microcentrifuge tubes as a cyclone separator effectively decreases the size and power consumption of the device; the SAW sensor in a well design and operating at 122 MHz was fabricated with MEMS techniques. After an explanation of the design of the cyclone separator, a simulation of the efficiency and the SAW sensor detection are discussed. A microcentrifuge tube (volume 0.2 mL, inlet and outlet diameters 0.5 mm) as a separator has separation cutoff diameters 50% (d50) at 2.5 μm; the required rate of volumetric flow at the inlet is 0.125 LPM, according to simulation with computational fluid dynamics (CFD) software; the surface-acoustic-wave (SAW) sensor exhibits sensitivity approximately 9 Hz/ng; an experiment for PM2.5 detection conducted with the combined device shows a strong positive linear correlation with a commercial aerosol monitor. The limit of detection (LOD) is 11 μg/m3 with sample time 160 s and total detection duration about 5 min.

scholarly journals Sensitivity Analysis of the Surface Acoustic Wave Sensor towards Size-Distributed Particulate Matter

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jian Yang ◽  
Jianan Lu ◽  
Shanmeng Zhang ◽  
Dong Guan
Keyword(s):  
Particulate Matter ◽  
Acoustic Wave ◽  
Frequency Shift ◽  
Size Distribution ◽  
Surface Acoustic Wave ◽  
Saw Sensor ◽  
Lognormal Size Distribution ◽  
Acoustic Wave Sensor ◽  
Distribution Parameters ◽  
Relationship Of

To study the sensitivity of the surface acoustic wave (SAW) sensor towards particulate matter (PM), an analytic model has been built based on single particle perturbation theory of full size range and the lognormal size distribution of the PM. The sensitivity of the frequency shift to 1 nanogram of PM has been calculated. The model shows that the frequency shift is a result of the competition between the negative perturbation by mass loading and the positive perturbation by elastic coupling, determined by particle size distribution parameters, material, and SAW frequency. To verify the model, the relationship of the frequency shift of a 315 MHz SAW to the concentration of aerosols generated by two kinds of powders of different sizes was measured. The experiment is in agreement with the model: the sensor has shown negative sensitivity towards aerosols generated by the finer particles of 1 μm, 3 μm polytetrafluoroethylene (PTFE), and A1 Arizona dust and positive sensitivity towards aerosols generated by the coarser particles of 10 μm PTFE and A4 Arizona dust; and the negative sensitivity is about 1 order higher than the positive.

A novel method of studying the micro-contact using surface acoustic wave sensor

Sensor Review ◽  
2016 ◽  
Vol 36 (4) ◽  
pp. 421-428 ◽  
Author(s):  
Jian Yang ◽  
Hejuan Chen
Keyword(s):  
Mechanical Properties ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Coupled System ◽  
Content Type ◽  
Saw Sensor ◽  
Micro Particles ◽  
Acoustic Wave Sensor ◽  
Coupling Stiffness ◽  
Novel Method

Purpose This paper aims to investigate the response behavior of the surface acoustic wave (SAW) sensor under the loading of micro-particles and to evaluate the feasibility of using the SAW sensor to study the micro-contact of the particle–plane interface. Design/methodology/approach An analytical perturbation theory of the coupled system of particle and SAW is presented. It shows that in the weak-coupling regime, the SAW sensor detects the coupling stiffness rather than the additional mass of the particle at the interface. The frequency perturbation formula expressed in parameters of the geometry and mechanical properties of the contact is further derived. The frequency shift of a 262-MHz Rayleigh-type SAW in the oscillation configuration under the loading of multiple starch particles of different sizes has been measured. Findings The experiment results of a linear relationship between the frequency increase and the sum of the radius of particles to the power of 2/3 verified the validity of the theory of linking the SAW response to the geometry and mechanical properties of the contact. Originality/value The SAW sensor could serve as a new candidate for studying the details of mechanical properties of the micro-contact of the interface.

scholarly journals Surface Acoustic Wave Sensors for Ammonia Detection at Room Temperature Based on SnO2/Co3O4 Bilayers

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Izabela Constantinoiu ◽  
Dana Miu ◽  
Cristian Viespe
Keyword(s):  
Thin Film ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Limit Of Detection ◽  
Positive Influence ◽  
Film Sensor ◽  
Frequency Shifts ◽  
Thin Film Sensor ◽  
Saw Sensor ◽  
The Difference

The selectivity of a SAW (surface acoustic wave) sensor, with a Co3O4 sensitive thin film for NH3 (ammonia) and the influence of SnO2 on its sensitivity, was studied. Thin films were deposited by pulsed laser deposition (PLD) on quartz SAW sensor substrates. Two sensors with different types of sensitive films were developed: a Co3O4 thin film sensor (S1) and a SnO2/Co3O4 thin film sensor (S2). The sensitive films were deposited in conditions which ensured a porous structure. The sensors were tested in the presence of three gases: NH3, methanol, and toluene. The selectivity of Co3O4 for NH3 was determined from the difference in the frequency shifts of the sensor for NH3 and for VOCs (volatile organic compounds). The positive influence of SnO2 on the sensitivity of sensor S2 was observed from the lower limit of detection (LOD) of this sensor and from the differences in frequency shifts between sensor S1 and sensor S2.

scholarly journals Love Wave Surface Acoustic Wave Sensor with Laser-Deposited Nanoporous Gold Sensitive Layer

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4492 ◽  
Author(s):  
Viespe ◽  
Dinca ◽  
Popescu-Pelin ◽  
Miu
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Love Wave ◽  
Limit Of Detection ◽  
Wave Surface ◽  
Sensitivity Limit ◽  
Sensitive Layer ◽  
Acoustic Wave Sensors ◽  
Acoustic Wave Sensor ◽  
Wave Sensors

Laser-deposited gold immobilization layers with different porosities were incorporated into Love Wave Surface Acoustic Wave sensors (LW-SAWs). Acetylcholinesterase (AChE) enzyme was immobilized onto three gold interfaces with different morphologies, and the sensor response to chloroform was measured. The response of the sensors to various chloroform concentrations indicates that their sensing properties (sensitivity, limit of detection) are considerably improved when the gold layers are porous, in comparison to a conventional dense gold layer. The results obtained can be used to improve properties of SAW-based biosensors by controlling the nanostructure of the gold immobilization layer, in combination with other enzymes and proteins, since the design of the present sensor is the same as that for a Love Wave biosensor.

scholarly journals Characteristics of Surface Acoustic Wave Sensors with Nanoparticles Embedded in Polymer Sensitive Layers for VOC Detection

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2401 ◽  
Author(s):  
Cristian Viespe ◽  
Dana Miu
Keyword(s):  
Acoustic Wave ◽  
Response Time ◽  
Frequency Shift ◽  
Surface Acoustic Wave ◽  
Limit Of Detection ◽  
Saw Sensor ◽  
Acoustic Wave Sensors ◽  
Volatile Organic ◽  
Wave Sensors ◽  
Better Than

Surface Acoustic Wave (SAW) sensors with several types of polymer sensing films, containing embedded Fe3O4 nanoparticles (NPs) with various dimensions and concentrations, were studied. A sensor with a sensing film consisting of the polymer alone was used for comparison. NPs with a mean diameter of 7 nm were produced by laser ablation with 5 ns pulse durations, and NPs with 13 nm diameters were obtained with a laser having 10 ps pulse durations. The properties of the Surface Acoustic Wave sensors with such sensing films were analyzed. Their response (frequency shift, sensitivity, noise and response time) to three different volatile organic components (VOCs) at various concentrations were compared with one another. The frequency shift and sensitivity increased with increasing NP concentration in the polymer for a given NP dimension and with decreasing NP diameter for a given concentration. The best results were obtained for the smallest NPs used. The SAW sensor containing 7 nm NPs had a limit of detection (LOD) of 65 ppm (almost five times better than the sensor with polymer alone), and a response time of about 9 s for ethanol.

scholarly journals Design of Surface Acoustic Wave Sensors Functionalized with Bisphenol S Based Molecules for Lead Ions Detection

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 872 ◽  
Author(s):  
Ghada Attia ◽  
Zineb Khaldi ◽  
Seyfeddine Rahali ◽  
Najla Fourati ◽  
Chouki Zerrouki ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Density Functional ◽  
Limit Of Detection ◽  
Lead Ions ◽  
Bisphenol S ◽  
Functional Theory ◽  
Saw Sensor ◽  
Acoustic Wave Sensors ◽  
Wave Sensors

This study concerns the design of surface acoustic wave sensors functionalized with bisphenol S based molecules for lead ions detection. (4-hydroxyphenyl, 4′-benzyloxyphenyl) sulfone (M1), (4-hydroxyphenyl,4′-anthrylmethyloxyphenyl) sulfone (M2) and (4,4′-bis (anthrylmethyloxyphenyl)) sulfone (M3) were synthesized and then drop-coated on the SAWs sensing areas. Gravimetric results indicate that the limit of detection of the three sensors is in the picomolar range and that the M3/SAW sensor has the highest affinity towards lead ions compared to M1/SAW and M2/SAW. Density functional theory (DFT) calculations were investigated to support experimental results and to understand the nature of interactions involved between lead ions and the three synthetized molecules.

scholarly journals Surface Acoustic Wave Sensor for C-Reactive Protein Detection

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6640 ◽  
Author(s):  
Ming-Jer Jeng ◽  
Mukta Sharma ◽  
Ying-Chang Li ◽  
Yi-Chen Lu ◽  
Chia-Yu Yu ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Insertion Loss ◽  
Protein Detection ◽  
Sensor Response ◽  
C Reactive Protein ◽  
Response Characteristics ◽  
Saw Sensor ◽  
Reactive Protein ◽  
Acoustic Wave Sensor

A surface acoustic wave (SAW) sensor was investigated for its application in C-reactive protein (CRP) detection. Piezoelectric lithium niobate (LiNbO3) substrates were used to study their frequency response characteristics in a SAW sensor with a CRP sensing area. After the fabrication of the SAW sensor, the immobilization process was performed for CRP/anti-CRP interaction. The CRP/anti-CRP interaction can be detected as mass variations in the sensing area. These mass variations may produce changes in the amplitude of sensor response. It was clearly observed that a CRP concentration of 0.1 μg/mL can be detected in the proposed SAW sensor. A good fitting linear relationship between the detected insertion loss (amplitude) and the concentrations of CRP from 0.1 μg/mL to 1 mg/mL was obtained. The detected shifts in the amplitude of insertion loss in SAW sensors for different CRP concentrations may be useful in the diagnosis of risk of cardiovascular diseases.

scholarly journals Detection of Volatile Organic Compounds Using Surface Acoustic Wave Sensor Based on Nanoparticles Incorporated in Polymer

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 373 ◽  
Author(s):  
Izabela Constantinoiu ◽  
Cristian Viespe
Keyword(s):  
Volatile Organic Compounds ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Organic Compounds ◽  
Limit Of Detection ◽  
Quartz Substrate ◽  
Laser Ablation Method ◽  
Best Response ◽  
Acoustic Wave Sensor ◽  
Volatile Organic

In this work, surface acoustic wave (SAW) sensors with two types of polymer sensing films, polyethyleneimine (PEI) and polydimethylsiloxane (PDMS), containing embedded ZnO, TiO2, and WO3 nanoparticles (NPs) for detecting volatile organic compounds (VOCs) were produced and studied. The NPs were obtained using the pulsed laser ablation method, with the same deposition conditions used for all three materials studied. After incorporation of the NPs into the polymer, the suspension obtained was deposited using the airbrush method onto the quartz substrate of the sensor. Sensors were tested for four types of VOCs: Ethanol, toluene, acetone, and dichloroethane. Those based on PEI-sensitive films showed a superior sensitivity to those with PDMS. It was also found that the sensors with WO3 NPs had the best results for ethanol, acetone, and dichloroethane. The limit of detection (LOD) of the PEI/WO3 sensor was 6 ppm for ethanol, 15 ppm for acetone, and 9 ppm for dichloroethane. For toluene, the best response was obtained using the PEI/ZnO sensor, which produced a LOD of 9 ppm.

Bilayer Structure Based Surface Acoustic Wave Sensor for Formaldehyde Detection

2013 ◽  
Vol 664 ◽  
pp. 986-989 ◽  
Author(s):  
Zhi Hua Ying ◽  
Jia Hu ◽  
Cong Ping Wu ◽  
Yi Qing Yang ◽  
Liang Zheng ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Room Temperature ◽  
High Sensitivity ◽  
Bilayer Structure ◽  
Coating Materials ◽  
Saw Sensor ◽  
Acoustic Wave Sensor ◽  
Recovery Times ◽  
Response And Recovery

This study contributes to the measurements of formaldehyde at room temperature. A bilayer structure based surface acoustic wave (SAW) sensor has been fabricated and experimentally studied. The coating materials carbon nanotubes (CNTs) and poly (4-vinylphenol) (P4VP) were deposited by a spray-painting method onto SAW sensors configured as 433.92MHz two-port resonator-based oscillators. The results display high sensitivity and entirely reversibility. The response and recovery times of the bilayer structure are very short, and the response values are obviously greater than plus of the two single layers. Some sensing mechanisms between analytes and the bilayer structure SAW sensor will be discussed preliminarily.

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